Fluidic circuits for sample preparation including bio-discs and methods relating thereto

Abstract

A fluidic circuit for receiving a fluid and separating a component of a fluid from the fluid comprises a separation chamber for receiving the fluid, an air chamber in fluid communication with the separation chamber, and a return channel in fluid communication with the separation chamber. In an advantageous embodiment, the fluidic circuit is subjected to a force, such as a centrifugal force, so that substantially all of the component of the fluid is moved to the return channel while substantially all remaining portions of the fluid are moved to the separation chamber.

1 . A fluidic circuit on a bio-disc for separating a component of a sample fluid, the fluidic circuit comprising: 
 a first main channel comprising 
 a separation chamber for receiving a sample fluid for processing, said separation chamber comprising an inlet port; and  
 an air chamber in fluid communication with said separation chamber, said air chamber configured to have a volume of air contained therein;  
   a second main channel connected to said first main channel comprising 
 a return section through which a separated component of the sample fluid flows for analysis;  
 one or more analysis sections in fluid communication with said return section, said one or more analysis sections having reagents deposited therein;  
 an entrance portion connected to said separation chamber and said return section, said return section in fluid communication with said first main channel through said entrance portion,  
   wherein said air chamber is configured to receive sample fluid from said separation chamber flows when said fluidic circuit is rotated such that the received sample fluid compresses said volume of air thereby providing pneumatic force that drives a separated component of the sample fluid through said entrance portion to said one or more analysis sections via said return section.    
     
     
         2 . The fluidic circuit of  claim 1 , wherein said entrance portion comprises an elbow section disposed such that a portion of said elbow section is disposed closer to the center of the bio-disc than the connection between said entrance portion and said separation chamber.  
     
     
         3 . The fluidic circuit of  claim 2 , wherein said elbow section comprises a hydrophobic barrier to prevent flow of a fluid from entering the return channel before separation of the component.  
     
     
         4 . The fluidic circuit of  claim 2 , wherein said elbow section comprises a filter element to prevent flow of a fluid from entering the return channel before separation of the component.  
     
     
         5 . The fluidic circuit of  claim 1 , wherein said second main channel further comprises a vent port.  
     
     
         6 . The fluidic circuit of  claim 1 , wherein the sample fluid is blood and the component of the fluid sample is serum.  
     
     
         7 . The fluidic circuit of  claim 1 , wherein the second main channel comprises a first analysis section having reagents for reverse typing, a second analysis section having reagents for glucose quantitation, and a third analysis section having reagents for cholesterol analysis.  
     
     
         8 . A fluidic circuit on a bio-disc for receiving a sample fluid and separating therefrom a component of the fluid, the fluidic circuit comprising: 
 a loading chamber for receiving a fluid sample, said loading chamber comprising an inlet port for introducing said fluid sample into said loading chamber;    a return channel comprising 
 a first end connected to said loading chamber;  
 a second end connected to the loading chamber, wherein said first end is connected to said loading chamber proximate to said inlet port and at a location closer to the center of the bio-disc than the location of said second end connection to said loading chamber,  
 wherein said first end is configured so that a first amount of a fluid sample loaded through the inlet port enters said first end of said return channel and a second amount of the fluid sample enters said second end of the return channel to thereby create an air lock within the return channel; and  
   an analysis chamber in fluid communication with said return channel through said second end, wherein the return channel is configured so that when the bio-disc is rotated, the first amount of fluid sample in the first end of the return channel moves into the loading chamber eliminating the air lock, and when the rotation is discontinued, at least a portion of the separated component enters the return channel through the second end of the return channel and flows to the analysis chamber by capillary action.    
     
     
         9 . The fluidic circuit of  claim 8 , further comprising an air chamber in fluid communication with said loading chamber, said air chamber having a volume of air, and wherein said loading chamber and said air chamber are configured such that a portion of the fluid introduced in said loading chamber flows into said air chamber and compresses said volume of air when said bio-disc is rotated, said compressed volume of air providing a pneumatic force that drives said at least a portion of the separated component into said return channel when the rotation of the bio-disc is reduced.  
     
     
         10 . The fluidic circuit of  claim 9 , wherein the sample fluid is blood and the separated component is serum.  
     
     
         11 . A fluidic circuit on a bio-disc configured to centrifuge the fluid by rotating the bio-disc and to effectuate the flow of at least a portion of the fluid to one or more chambers for further processing or analysis, comprising: 
 a fluid channel configured to receive a sample fluid;    at least one chamber for processing a portion of the sample fluid; and    an air chamber in fluid communication with said fluid channel, said air chamber having a volume of air contained therein, wherein the fluid channel and said air chamber are configured such that a portion of the sample fluid introduced in said fluid channel flows into said air chamber and compresses said volume of air when said fluidic circuit is rotated, said compressed volume of air providing a pneumatic force that drives at least a portion of the sample fluid to said at least one chamber for further processing or analysis.    
     
     
         12 . The fluidic circuit of  claim 11 , wherein said air chamber is sealed except for a portion of said air chamber which is in fluid communication with said first fluid channel.